Current techniques for evaluation of internal derangements of the temporomandibular joint (TMJ) require a combination of radiograph procedures, including transcranial or pantographic x-rays, tomograms, arthrography and possibly CT. Magnetic resonance imaging (MRI) is an alternative technique for viewing the soft tissues of the joint without exposure to ionizing radiation. Preliminary MR scans of human TMJ's (1.5 Tesla, using 6 cm surface coils signal detectors) produced highly detailed images. However, accurate identification of small structures within the joint capsule, such as the sections of the meniscus, requires further study prior to clinical application. Because the MR image is based on signals which reflect complex characteristics of the tissues related to their physiology as well as structure, variations between individuals and between healthy and diseased structures may occur. Limited data is currently available relating MR signal strength and tissue characteristics. This project will investigate the potential use of MR to detect derangement of the TMJ soft tissues and to provide information regarding the degree of pathology in the meniscus and posterior ligament tissues. Anatomic relationships as shown in MR images of fresh cadaver TMJ's will be compared with gross morphology, dissection and histological evaluation. Further, the MR signal characteristics of fresh, surgically excised meniscal and posterior ligament tissue will be correlated with detailed histological assessment of these tissues using standard histological procedures and stereometric image analysis. Finally, MR scanning of a limited number of human subjects with and without intracapsular pathology will be performed to corroborate the results of the in vitro studies and determine the appropriateness of future studies of the clinical efficacy of MRI for evaluation of specific forms of temporomandibular joint dysfunction. Surgical verification and tissue samples will be obtained from 2/3 of the subjects. This investigation represents a collaboration between the Univ. of Penna. Schools of Medicine and Dental Medicine and the School of Dentistry at the S.U.N.Y. at Buffalo. The investigators at the Univ. of Penna. have extensive expertise and unique MR imaging facilities for magnetic resonance studies, while the investigators at S.U.N.Y. have sophisticated automated histology equipment and a large resource for TMJ patients.